The world we hear is rarely simple — sounds overlap in space and time, and the brain must constantly decide what matters. The Caras Lab studies how past experience and current context reshape the way the brain represents sound. Our work applies rigorous behavioral approaches and modern neuroscience tools to the Mongolian gerbil, a powerful model for human hearing, to better understand how dynamic changes in sound perception arise. Ongoing projects in the lab seek to answer the following questions:

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How does the brain learn to hear better?
With practice, you can improve your ability to hear sound features that were previously imperceptible. In a classic example of this phenomenon, a highly trained musician can detect subtle changes in pitch or rhythm that are missed by the untrained ear. During this process, neurons across the auditory pathway — from midbrain to thalamus to cortex — become sharper and more selective, changes that track improvements in perception itself. We're mapping where these changes occur, how they're coordinated across brain regions and cortical layers, and which are truly necessary for learning.

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What tells the brain a sound is worth hearing?

Stop and listen. Do you suddenly hear that bird outside the window? That clock ticking on the wall? The hum of the refrigerator?  Sound perception can shift in an instant as a result of sudden changes in attention and expectation. We're working to uncover how the brain flags which sounds are behaviorally important and communicates that priority across brain regions, with the goal of understanding how this signaling can be harnessed to sharpen attention and speed learning on demand.

 

How does the brain protect what is learned?

Learning requires flexibility, but memories need stability. We're investigating the extracellular mechanisms that let the brain stay open to change while acquiring a new skill, then lock that skill in once it's mastered — work aimed at eventually allowing us to reopen these windows of flexibility when needed, or shield hard-won skills from being lost.